Small Disturbance Stability Analysis Of Power Systems For Large-scale PV Grid Connection And Its Application

With the gradual depletion of fossil energy sources and the growing severity of environmental problems,the demand for new energy development is increasing.The randomness and uncertainty of photovoltaic power generation make its large-scale grid connection have a great impact on the problem of small disturbance stability of power.To address the impact of grid-connected PV on system stability,this thesis uses damping ratio sensitivity to determine the best access method for PV power generation to ensure system stability with small disturbances and establishes a detailed model for PV.Firstly,the damping ratio sensitivity of PV grid connection at different nodes is solved by using the random excitation of PV power fluctuation as the ingestion quantity,then the optimal PV grid connection node is selected according to the magnitude of the damping ratio sensitivity,and the optimal PV connection method is obtained by determining the PV connection location and capacity through the optimization method.The New England 10-machine 39-node system and an actual power system in a western province are used as examples to verify the effectiveness of the algorithm in this paper.Finally,Matlab/Simulink is used to establish a dynamic model of the PV plant and analyse the impac t of large-scale PV access to a multi-machine system on the stability of the system with small disturbances,verifying the effectiveness of the optimal PV access method and providing a new idea for the study of PV grid connection.